<template>
    <view
        class="tui-tabs-view"
        :class="[
            isFixed ? 'tui-tabs-fixed' : 'tui-tabs-relative',
            unlined ? 'tui-unlined' : ''
        ]"
        :style="{
            width: tabsWidth + 'px',
            height: height + 'rpx',
            padding: `0 ${padding}rpx`,
            background: backgroundColor,
            top: isFixed ? top + 'px' : 'auto',
            zIndex: isFixed ? zIndex : 'auto'
        }"
    >
        <view
            v-for="(item, index) in swiperTabs"
            :key="index"
            class="tui-tabs-item"
            :style="{
                width: itemWidth
            }"
            @tap.stop="swichTabs(index)"
        >
            <view
                class="tui-tabs-title"
                :class="{
                    'tui-tabs-active': currentTab == index,
                    'tui-tabs-disabled': item.disabled
                }"
                :style="{
                    color: currentTab == index ? selectedColor : color,
                    fontSize: size + 'rpx',
                    lineHeight: size + 'rpx',
                    fontWeight: bold && currentTab == index ? 'bold' : 'normal'
                }"
            >
                {{ item.name }}
            </view>
        </view>
        <view
            class="tui-tabs-slider"
            :style="{
                transform: 'translateX(' + scrollLeft + 'px)',
                width: sliderWidth + 'rpx',
                height: sliderHeight + 'rpx',
                borderRadius: sliderRadius,
                bottom: bottom,
                background: sliderBgColor,
                marginBottom:
                    bottom == '50%' ? '-' + sliderHeight / 2 + 'rpx' : 0
            }"
        ></view>
    </view>
</template>

<script>
export default {
    name: 'tuiTabs',
    props: {
        //标签页
        swiperTabs: {
            type: Array,
            default() {
                return []
            }
        },
        //tabs宽度，不传值则默认使用windowWidth，单位px
        width: {
            type: Number,
            default: 0
        },
        //rpx
        height: {
            type: Number,
            default: 80
        },
        //rpx 只对左右padding起作用，上下为0
        padding: {
            type: Number,
            default: 30
        },
        //背景色
        backgroundColor: {
            type: String,
            default: '#FFFFFF'
        },
        //是否固定
        isFixed: {
            type: Boolean,
            default: false
        },
        //px
        top: {
            type: Number,
            // #ifndef H5
            default: 0,
            // #endif
            // #ifdef H5
            default: 44
            // #endif
        },
        //是否去掉底部线条
        unlined: {
            type: Boolean,
            default: false
        },
        //当前选项卡
        currentTab: {
            type: Number,
            default: 0
        },
        //滑块宽度
        sliderWidth: {
            type: Number,
            default: 68
        },
        //滑块高度
        sliderHeight: {
            type: Number,
            default: 6
        },
        //滑块背景颜色
        sliderBgColor: {
            type: String,
            default: '#5677fc'
        },
        sliderRadius: {
            type: String,
            default: '50rpx'
        },
        //滑块bottom
        bottom: {
            type: String,
            default: '0'
        },
        //标签页宽度
        itemWidth: {
            type: String,
            default: '25%'
        },
        //字体颜色
        color: {
            type: String,
            default: '#666'
        },
        //选中后字体颜色
        selectedColor: {
            type: String,
            default: '#5677fc'
        },
        //字体大小
        size: {
            type: Number,
            default: 28
        },
        //选中后 是否加粗 ，未选中则无效
        bold: {
            type: Boolean,
            default: false
        },
        zIndex: {
            type: [Number, String],
            default: 996
        }
    },
    watch: {
        currentTab() {
            this.checkCor()
        },
        tabs() {
            this.checkCor()
        },
        width(val) {
            this.tabsWidth = val
            this.checkCor()
        }
    },
    created() {
        // 高度自适应
        setTimeout(() => {
            uni.getSystemInfo({
                success: res => {
                    this.winWidth = res.windowWidth
                    this.tabsWidth =
                        this.width == 0 ? this.winWidth : this.width
                    this.checkCor()
                }
            })
        }, 0)
    },
    data() {
        return {
            winWidth: 0,
            tabsWidth: 0,
            scrollLeft: 0
        }
    },
    methods: {
        checkCor: function() {
            let tabsNum = this.swiperTabs.length
            let padding = (this.winWidth / 750) * this.padding
            let width = this.tabsWidth - padding * 2
            let left =
                (width / tabsNum - (this.winWidth / 750) * this.sliderWidth) /
                    2 +
                padding
            let scrollLeft = left
            if (this.currentTab > 0) {
                scrollLeft = scrollLeft + (width / tabsNum) * this.currentTab
            }
            this.scrollLeft = scrollLeft
        },
        // 点击标题切换当前页时改变样式
        swichTabs: function(index) {
            let item = this.swiperTabs[index]
            if (item && item.disabled) return
            if (this.currentTab == index) {
                return false
            } else {
                this.$emit('slideTuiTab', {
                    index: Number(index)
                })
            }
        }
    }
}
</script>

<style scoped>
.tui-tabs-view {
    width: 100%;
    box-sizing: border-box;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.tui-tabs-relative {
    position: relative;
}

.tui-tabs-fixed {
    position: fixed;
    left: 0;
}

.tui-tabs-fixed::before,
.tui-tabs-relative::before {
    content: '';
    position: absolute;
    border-bottom: 1rpx solid #eaeef1;
    -webkit-transform: scaleY(0.5) translateZ(0);
    transform: scaleY(0.5) translateZ(0);
    transform-origin: 0 100%;
    bottom: 0;
    right: 0;
    left: 0;
}

.tui-unlined::before {
    border-bottom: 0 !important;
}

.tui-tabs-item {
    display: flex;
    align-items: center;
    justify-content: center;
}

.tui-tabs-disabled {
    opacity: 0.6;
}

.tui-tabs-title {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    z-index: 2;
}

.tui-tabs-active {
    transition: all 0.15s ease-in-out;
}

.tui-tabs-slider {
    position: absolute;
    left: 0;
    transition: all 0.15s ease-in-out;
    z-index: 0;
    transform: translateZ(0);
}
</style>
